Exam 4: Discrete Random Variables

According to data from a federal blood program, 40% of all individuals have type A blood. If six individuals give blood, find the probability -None of the individuals has type A blood?

One fair die is thrown.What is the expected value of the number of dots on the top face of the die?

If the probability distribution of X is: () 0 0.1 1 0.2 2 0.3 3 0.4 -What is the expected value of X?

Which of the following variables could be a binomial random variable?

A courier company has established a record in a major city for delivering 90% of its packages the next working day. -Calculate the standard deviation of the number delivered.

Historical data shows that the average number of patient arrivals at the intensive care unit of General Hospital is 3 patients every 2 hours.Assume that the patient arrivals are distributed according to Poisson distribution. -Determine the probability of at least 4 but no more than 8 patients arriving in a three-hour period.

The J.O. Supplies Company buys calculators from a foreign supplier. The probability of a defective calculator is 10%. -If 3 calculators are selected at random,what is the probability that one of the calculators will be defective?

A class of 20 students;8 male and 12 female.If you select 8 students at random,what is the probability that at least 3 of them will be male?

A batch has just been completed.What is the probability that the first three units manufactured in this batch will contain at least a total of 4 defects?

The variable "home ownership" can take on one of two values,1 if the person living in a home owns the home and zero if the person living in a home does not own the home is an example of a discrete random variable.

A pharmaceutical company has determined that if a new cholesterol-reducing drug is manufactured (introduced to the market),the following probability distribution will describe this drug's contribution to the company's profits during the next six months. Profit Contribution Probability of profit contribution -\ 30,000 .20 \ 50,000 .50 \ 200,000 .30 The company management has decided to market this product if the expected contribution to profit for the next six months is more than $90,000.Based on the information given above,should the company begin manufacturing the new drug?

A Poisson random variable is a continuous variable that can be used to describe the number of occurrences of an event over a specified interval of time or space.

Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store.Determine the expected number of customer arrivals for a five-minute period

The J.O. Supplies Company buys calculators from a foreign supplier. The probability of a defective calculator is 10%. -If 10 calculators are selected at random,what is the probability that 3 or more of the calculators will be defective?

If p = .1 and n = 5,then the corresponding binomial distribution is _____.

Determine the probability that a 3 will appear twice,if a fair die is rolled 10 times.

For a binomial experiment, the probability of success is 40% and the number of trials is 5. Let X represent the number of successes. -Find P(X > 4).

Assume the number of trucks passing an intersection has a Poisson distribution with mean of 5 trucks per minute.What is the probability of 0 or 1 trucks in one minute?

Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute: -Find the variance of X.

A large disaster cleaning company estimates that 30% of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that is has contracted: -Calculate the probability that exactly 4 of the jobs were not completed within the bid time.